From 67f74302f45d5d862f22ced3297624e50ac352f0 Mon Sep 17 00:00:00 2001 From: Christian König Date: Tue, 7 Dec 2021 10:10:15 +0100 Subject: drm/nouveau: wait for the exclusive fence after the shared ones v2 Always waiting for the exclusive fence resulted on some performance regressions. So try to wait for the shared fences first, then the exclusive fence should always be signaled already. v2: fix incorrectly placed "(", add some comment why we do this. Signed-off-by: Christian König Tested-by: Stefan Fritsch Tested-by: Dan Moulding Acked-by: Ben Skeggs Signed-off-by: Christian König Cc: Link: https://patchwork.freedesktop.org/patch/msgid/20211209102335.18321-1-christian.koenig@amd.com --- drivers/gpu/drm/nouveau/nouveau_fence.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c b/drivers/gpu/drm/nouveau/nouveau_fence.c index 05d0b3eb3690..0ae416aa76dc 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fence.c +++ b/drivers/gpu/drm/nouveau/nouveau_fence.c @@ -353,15 +353,22 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e if (ret) return ret; - } - fobj = dma_resv_shared_list(resv); - fence = dma_resv_excl_fence(resv); + fobj = NULL; + } else { + fobj = dma_resv_shared_list(resv); + } - if (fence) { + /* Waiting for the exclusive fence first causes performance regressions + * under some circumstances. So manually wait for the shared ones first. + */ + for (i = 0; i < (fobj ? fobj->shared_count : 0) && !ret; ++i) { struct nouveau_channel *prev = NULL; bool must_wait = true; + fence = rcu_dereference_protected(fobj->shared[i], + dma_resv_held(resv)); + f = nouveau_local_fence(fence, chan->drm); if (f) { rcu_read_lock(); @@ -373,20 +380,13 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e if (must_wait) ret = dma_fence_wait(fence, intr); - - return ret; } - if (!exclusive || !fobj) - return ret; - - for (i = 0; i < fobj->shared_count && !ret; ++i) { + fence = dma_resv_excl_fence(resv); + if (fence) { struct nouveau_channel *prev = NULL; bool must_wait = true; - fence = rcu_dereference_protected(fobj->shared[i], - dma_resv_held(resv)); - f = nouveau_local_fence(fence, chan->drm); if (f) { rcu_read_lock(); @@ -398,6 +398,8 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e if (must_wait) ret = dma_fence_wait(fence, intr); + + return ret; } return ret; -- cgit v1.2.3